Brassica vegetable supplement and process for manufacture

ABSTRACT

A brassica vegetable tablet contains at least 50 ug of sulforaphane and a maximum of 50 ug of sulforaphane-nitrile. A process for producing a brassica vegetable product includes inactivating endogenous myrosinase enzyme in a brassica vegetable and thereafter blending the vegetable with exogenous myrosinase enzyme. The preferred process may include steam blanching as the method of inactivating the endogenous myrosinase enzyme. The preferred process may also include horseradish root as the source of exogenous myrosinase enzyme.

BACKGROUND OF THE INVENTION

The present invention relates to a brassica vegetable concentrate andsupplement containing high levels of sulforaphane and minimal levels ofsulforaphane-nitrile and the method of making it.

Although consumers are increasingly more aware of the relationship ofbrassica vegetables to health and disease, many people don't reap thesebenefits because they don't like the taste of the vegetables or theyfind them cumbersome to eat. Broccoli, as well as other brassicavegetables, may be helpful in fighting disease because they containglucosinolates. Glucosinolates are converted to isothiocyanates, such assulforaphane, by myrosinase enzymes, a group of enzymes that arenaturally present in brassica vegetables. Sulforaphane and otherisothiocyanates help the body to fight disease by inducing a group ofenzymes capable of detoxifying carcinogens in the body.

Unfortunately for consumers, myrosinase enzymes contact theglucosinolate when the cells of the brassica vegetable are disruptedsuch as by chewing or milling. Therefore, those consumers who don't likethe taste of broccoli, yet don't want to pass up its health benefits,must force themselves to eat something they don't like. In addition,glucosinolates can also be converted by myrosinase enzymes into nitrilessuch as sulforaphane-nitrile, non-nutrients that are contraindicated forhealth. Therefore, there is a need for a brassica supplement that hashigh levels of sulforaphane but low levels of sulforaphane-nitrile.

At the present time, a suitable brassica vegetable supplement orconcentrate is not available. Typically, prior art brassica tablets,such as broccoli tablets, are made by dehydrating the fresh vegetable,grinding the vegetable into a powder form and thereafter forming atablet or supplement. High temperature dehydration, however, inactivatesthe endogenous (naturally present) myrosinase enzymes. Consequently, itis hypothesized that when the supplement is ingested, the conversion ofthe glucosinolates to isothiocyanates cannot occur via theaforementioned plant pathway. It has also been suggested to makebrassica tablets by freeze-drying the vegetable. In this method, theendogenous myrosinase enzymes are not inactivated in the final product.However, the enzymes contained in the tablet are not active at the lowpH of stomach acids (when the supplement is swallowed before it canconvert the glucosinolates into isothiocyanates).

A process that produces a brassica vegetable supplement or concentratewith high levels of sulforaphane and minimal sulforaphane-nitrile isdesired. Such a process should maximize the conversion of the parentglucosinolates (gluocoraphanin) to sulforaphane while minimizing thepresence of sulforaphane-nitrile. Therefore, the resulting supplement orconcentrate must contain preformed sulforaphane in lieu of the parentglucosinolate and corresponding myrosinase enzymes where conversion issubject to environmental conditions.

SUMMARY OF THE INVENTION

The present invention includes a brassica vegetable supplement orconcentrate and a method of making it. The brassica vegetable supplementof the present invention comprises at least 50 ug of sulforaphane and amaximum of 50 ug of sulforaphane-nitrile. More preferably, the tabletcomprises at least 100 ug of sulforaphane and no more than 20 ug ofsulforaphane-nitrile. In the most preferred embodiment, the tabletincludes 1,000 ug of sulforaphane and a maximum of 10 ugsulforaphane-nitrile.

The process for producing the brassica vegetable supplement of thepresent invention includes inactivating the endogenous myrosinaseenzymes in brassica vegetables and thereafter blending the vegetableswith exogenous sources of myrosinase enzymes. More specifically, theprocess of the present invention includes harvesting broccoli tominimize broccoli stem material, blanching fresh broccoli to inactivateendogenous myrosinase enzymes, blending the steamed broccoli with asource of exogenous myrosinase enzymes, preparing a homogenate from theblended broccoli and exogenous myrosinase enzymes, centrifuging thehomogenate, concentrating the supernatant by low heat vacuumconcentration, adding a carrier such as starch, maltodextrin, sucrose,dextrose anti vegetable gums to the concentrated supernatant, loweringthe pH to 3.5, forming a powder by drying the concentrate and carrier,and forming a tablet from the powder.

One of the advantages of the process of the present invention is that itmaximizes the conversion of glucoraphanin (a specific glucosinolate) tosulforaphane while minimizing the presence of sulforaphane-nitrile.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS OF THE INVENTION

The present invention includes a brassica vegetable supplement with highlevels of sulforaphane and low levels of sulforaphane-nitrile. Theprocess for making the product comprises inactivating endogenousmyrosinase enzymes in brassica vegetables and blending the vegetableswith active exogenous myrosinase enzymes.

In particular, the brassica vegetable product is a supplement productwhich can take any form such as liquid, powder, tablet or capsulecontaining sulforaphane levels of 50 ug with no more than 50 ugsulforaphane-nitrile. More preferably, the tablet contains 100 ug ofsulforaphane and a maximum of 20 ug of sulforaphane-nitrile. Mostpreferably, the tablet contains 1,000 ug of sulforaphane and a maximumof 10 ug of sulforaphane-nitrile.

The preparations and products of the present invention may vary widelyin composition. The process requires brassica vegetables. Brassicavegetables include, but are not limited to, cabbage, kale, cauliflower,broccoli, mustard greens, kohlrabi, Brussels sprouts, turnips andhorseradish root. The most desirable brassica vegetable for this processis broccoli. Although the entire broccoli plant may be used, thebroccoli floret is preferred as it has been found that the stem materialcontains more nitrile than the floret. In the following discussion, theprocess for making the supplement of the present invention will bedescribed with reference to broccoli. It is to be understood however,that the use of the other brassica vegetables is contemplated.

The broccoli must be treated so that its endogenous myrosinase enzymesare inactivated. Inactivation may occur by any method presently known inthe art including, but not limited to, steaming, blanching and immersingin ethanol. In the preferred method, the broccoli is steam blanched.Steam blanching preferably occurs at a temperature in the range of80°-100° C., more preferably in the range of 90°-100° C, and mostpreferably at 100° C. The duration of steam blanching also affects thedeactivation of the myrosinase enzymes. Steam blanching thereforeproceeds for at least 0.5-15 min., more preferably 2.0-8 min., and mostpreferably 3-5 min.

After the broccoli has been steamed at the requisite temperature and fora duration sufficient to inactivate the myrosinase enzymes, exogenousmyrosinase enzyme and water are added. The exogenous myrosinase enzymemay be taken from any source, natural or commercial. An example of acommercial variety of myrosinase enzyme is thioglucosidase from SigmaChemical Co., St. Louis, Mo., EC 3.2.3.1. Preferably, the exogenousmyrosinase enzyme is taken from a natural source, more preferably form abrassica vegetable such as, but not limited to, broccoli, kale, Brusselssprouts, turnips, cabbage leaves, cauliflower, mustard greens, kohlrabi,and horseradish root. The most preferable source of exogenous myrosinaseenzyme for this process is fresh horseradish root. Preferably, freshhorseradish is added to fresh, blanched broccoli in the range of 3-10%,and more preferably is added in the range of 3-8%. Most preferably,fresh horseradish is added to broccoli in the range of 4-6%, withoptimum being 5%. The blanched vegetables, exogenous myrosinase enzymeand water are then milled. Milling may occur by any method known in theart. Preferably, an Urshell Mill is used (with a 0.030" screen) topre-mill the material with the added water. The pre-milled material isthen put through a colloid mill to form a very fine slurry. The slurryis then mixed in a tank for approximately 0.5-3 hours, more preferably1-2 hours, and most preferably 2 hours.

After the exogenous myrosinase enzymes, water and blanched vegetablesare sufficiently mixed, the mixture is centrifuged, the supernatantconcentrated, the pH is adjusted, and, thereafter, processed to form apowder. This may be accomplished by any method known in the art.Preferably, the concentrate is mixed with a carrier. Any carrier willwork, and preferably a carrier selected from the group consisting ofsucrose, dextrose, starch and vegetable gums can be used. The mixture isthen dried through any conventional method such as freeze drying, orspray drying, with spray drying being the preferred method.Alternatively, prior to drying, the pH of the concentrate is adjusted to3.5. The powder may be further processed into any form appropriate forconsumer use, such as powdered food and beverage supplements, tabletsand capsules. Preferably, a broccoli tablet is formed.

The process of the present invention is an improvement over the priorart because it maximizes the conversion of glucoraphanin to sulforaphanewhile minimizing the presence of sulforaphane-nitrile. Specifically, theprocess inhibits the conversion of glucoraphanin to sulforaphane-nitrileby inactivating the endogenous myrosinase enzyme. The glucoraphanin isthen converted to sulforaphane by the addition of exogenous myrosinaseenzymes.

Although the present invention has been disclosed with respect to apreferred embodiment, further modifications will be apparent to thoseskilled in the art. Accordingly, it is not intended that the inventionbe limited by the disclosure or by such modifications, but instead thatits scope should be determined entirely by reference to the claims whichfollow herein below.

What is claimed:
 1. A process for producing a brassica vegetable productwith high levels of sulforaphane and low levels of sulforaphane-nitrilecomprising the steps of:(a) deactivating endogenous myrosinase enzyme ina brassica vegetable; and (b) blending the vegetable with exogenousmyrosinase enzyme, wherein the product contains at least about 50 μg ofsulforaphane and a maximum of about 50 μg sulforaphane-nitrile.
 2. Theprocess for producing the brassica vegetable product of claim 1 whereinthe endogenous myrosinase enzyme is inactivated by steam blanching. 3.The process for producing a brassica vegetable product of claim 1wherein the brassica vegetable is selected from the group consisting ofcabbage, Brussels sprouts, kale, cauliflower, turnip, broccoli, mustardgreens, kohlrabi, and horseradish root.
 4. The process for producing thebrassica vegetable product of claim 1 wherein the brassica vegetable isbroccoli.
 5. The process for producing the brassica vegetable product ofclaim 1 wherein the source of exogenous enzyme is a brassica vegetableor mixture thereof.
 6. A process for producing a brassica vegetableproduct with high levels of sulforaphane and low levels ofsulforaphane-nitrile comprising the steps of:(a) deactivating endogenousmyrosinase enzyme in a brassica vegetable; and (b) blending thevegetable with exogenous myrosinase enzyme.
 7. The process for producingthe brassica product of claim 6 wherein the endogenous myrosinase enzymeis inactivated by steam blanching.
 8. The process for producing thebrassica vegetable product of claim 6 wherein the brassica vegetable isselected from the group consisting of cabbage, Brussels sprouts, kale,cauliflower, turnip, broccoli, mustard greens, kohlrabi and horseradishroot.
 9. The process for producing the brassica vegetable product ofclaim 6 wherein the brassica vegetable is broccoli.
 10. The process forproducing the brassica vegetable product of claim 6 wherein the sourceof the exogenous enzyme is a brassica vegetable or mixtures thereof. 11.The process for producing the brassica vegetable product of claim 6wherein the source of the exogenous enzyme is horseradish root.
 12. Theprocess of claim 6 wherein the brassica vegetable product contains atleast about 50 ug sulforaphane and a maximum of about 50 ugsulforaphane-nitrile.
 13. The process for producing the brassica productof claim 6 further comprising the steps of:(a) preparing a slurry fromthe blended vegetable and exogenous enzyme; (b) passing the slurrythrough a centrifuge; (c) preparing a powder from the supernatant; and(d) forming the powder into a tablet.
 14. A process for producing abroccoli tablet with high levels of sulforaphane and low levels ofsulforaphane-nitrile comprising the steps of:(a) steaming fresh broccolito inactivate endogenous myrosinase enzyme; (b) blending the blanchedbroccoli with a source of exogenous myrosinase enzyme; (c) preparing aslurry from the blended broccoli and exogenous myrosinase enzyme; (d)passing the slurry through a centrifuge; (e) forming a powder from thesupernatant; and (f) forming a broccoli tablet from the powder, whereinthe tablet contains at least about 50 ug sulforaphane and a maximum ofabout 50 ug sulforaphane-nitrile.
 15. The process recited in claim 14wherein the steaming is performed at a temperature of about 100° C. 16.The process of claim 14 wherein the source of exogenous myrosinaseenzyme is horseradish root.
 17. A process for preparing a broccolitablet with high levels of sulforaphane and low levels ofsulforaphane-nitrile comprising the steps of:(a) inhibiting conversionof glucoraphanin in fresh broccoli to sulforaphane-nitrile byinactivating myrosinase enzymes in the broccoli; (b) convertingglucoraphanin in fresh broccoli to sulforaphane by adding exogenousmyrosinase enzymes; and (c) preparing a tablet.
 18. A brassica vegetabletablet comprising at least about 50 ug by weight of sulforaphane and amaximum of about 50 ug by weight of sulforaphane-nitrile prepared by aprocess comprising the steps of:(a) inactivating endogenous myrosinaseenzyme in a brassica vegetable; and (b) blending the vegetable withexogenous myrosinase enzyme.
 19. The brassica vegetable tablet preparedby the process of claim 18 wherein the endogenous myrosinase enzyme isinactivated by steam blanching.
 20. The brassica vegetable tabletprepared by the process of claim 18 wherein the endogenous myrosinaseenzyme is inactivated by immersing the brassica vegetable in ethanol.21. The brassica vegetable tablet prepared by the process of claim 18wherein the endogenous myrosinase enzyme is inactivated by waterblanching.
 22. The brassica vegetable tablet prepared by the process ofclaim 18 wherein the brassica vegetable is selected from the groupconsisting of cabbage, Brussels sprouts, kale, cauliflower, turnip,broccoli, mustard greens, kohlrabi and horseradish root.
 23. Thebrassica vegetable tablet prepared by the process of claim 18 whereinthe brassica vegetable is broccoli.
 24. The brassica vegetable tabletprepared by the process of claim 18 wherein the source of the exogenousenzyme is a brassica vegetable or mixtures thereof.
 25. The brassicavegetable tablet prepared by the process of claim 18 wherein the sourceof the exogenous enzyme is horseradish root.
 26. The brassica vegetabletablet prepared by the process of claim 18 comprising the steps of:(a)preparing a slurry from the blended vegetable and exogenous enzyme; (b)passing the slurry through a centrifuge; (c) preparing a powder from thesupernatant; and (d) forming the powder into a tablet.
 27. The processfor producing the brassica vegetable product of claim 1 wherein thesource of exogenous enzyme is horseradish root.
 28. The process forproducing the brassica vegetable product of claim 1 further comprisingthe steps of:(a) preparing a slurry from the blended vegetable andexogenous enzyme; (b) passing the slurry through a centrifuge; (c)preparing a powder from the supernatant; and (d) forming the powder intoa tablet.
 29. A process for preparing a broccoli tablet with high levelsof sulforaphane and low levels of sulforaphane-nitrile comprising thesteps of:(a) inhibiting conversion of glucoraphanin in fresh broccoli tosulforaphane-nitrile by inactivating myrosinase enzymes in the broccoli;(b) converting glucoraphanin in fresh broccoli to sulforaphane by addingexogenous myrosinase enzymes; and (c) preparing a tablet, wherein saidtablet contains at least about 50 ug sulforaphane and a maximum of about50 ug of sulforaphane-nitrile.